Semiconductor chip manufacturing may include processes and sub-processes for fabrication of the chip which require testing of singular semiconductor chips as a stand alone and not connected to one or more chips, for example in a stacked configuration. Similarly, testing of the chip may be required when the chip is in a stacked configuration connected to one or more chips in a package.
During the process of fabricating a three dimensional stack of semiconductor chips, there may be a need to operate a chip, or a specific circuit blocks in a chip, in different modes when the chip is tested alone, that is, as a stand alone, as opposed to when the chip is tested in a stacked configuration, that is, connected to other chips. In addition, for electrical test purposes, it may be necessary to identify if a chip is stacked, that is, connected to one or more other chips, or in a stand alone configuration.